Electric heater



Aug. 20, 1957 w. M. GERMON 2,803,734- ELECTRIC HEATER Filed Aug. 7, 1956 INVENTOR hsleyM German ELECTRIC HEATER Wesley M. Gerrnon, Wellsburg, W. Va.

Application August 7, 1956, SerialNo. 602,545

1 Claim. (Cl. 219-19) ance unit. With a view towards overcoming the above noted disadvantages of electric heaters, it has been proposed to provide heaters containing a body of liquid which is vaporized 'by electrical energy and to circulate the air of the room over finned tubes through which the vapors pass, thus heating the air and condensing the 'vapors;'the condensateis returned to the body of liquid to here-vaporized. Such heaters have the objection that theyare needlessly complex, relatively expensive to construct and involve the handling of substantial amounts of liquid with the attendant danger of spillage and also the attendant dangers inherent in the relatively high pressures which may be generated when the liquid is vaporized or re-vaporized.

It is among the objects of the present invention to provide an efficient electrical heater, eminently suited for use as a household heater, which is exceptionally safe in op eration, particularly in that it involves no fire or explosion hazardsand subatmospheric pressure conditions Within the heater when. inuseandwhich heater in operation. does not require the maintenance .of a body of vaporizable liquid within-the heater.

Stillanother objectof-this invention is to providesuch heater in -which theelectrical resistance unit doesnot come into contact with the air of the room in which the heater may be disposed.

For a fuller understanding of the nature and objects of this invention, reference should be had to the following detailed description taken in connection with the accompanying drawing, in which:

Figure l is an elevational view of a heater embodying this invention;

Figure 2 is a fragmentary vertical section on an enlarged scale through the heater of Figure l; and

Figure 3 is a transverse section, partly in elevation, taken on a plane passing through line 3-3 on Figure 2.

Referring to the drawing, indicates a casing or tube, preferably but not necessarily cylindrical, which may be suitably dimensioned. Thus, for example, it may have a diameter of approximately 4" and a length of about 3 feet; it will be understood that these dimensions are given for purposes of exemplification only, and that casing 10 of the heater may be of any desired dimensions. Casing 10 is provided with end walls 11 and 12 which, together with the cylinder wall 13 of the casing, define a gas tight enclosed space or zone 14 within the casing. Pins 15 are brazed or otherwise suitably secured to the periphery of casing 13 in closely spaced relation to provide eflicient heat transfer and radiation surfaces as shown in Figure 1. These fins are closely spaced along substantially the entire length of the casing 13 to permit flow of air thereover in the openings 16 in the end walls 11: and12.

2,803,734 Patented Aug. 20, 1957 eflicient heat transfer relationship so as to effectively heat the air in the room in which the heater is disposed.

Each of the end walls 11 and 12 is provided with a threaded opening 16 in which is disposed a threaded plug 17 provided with apolygonal socket 18 for the reception spaced supports 20 along its length to prevent the tube 21 from contacting the inner Wall of casing 10. Packing 19 insures a gas tight seal between the tube 21 and the end walls 11 and 12.

Resistance wire 23 runs the full length of tube 21 and is insulated from the walls of the tube 21 by heat-resisting, i.-e., will not decompose at elevated temperatures, and heat-conducting insulation 24. 'For example, the insulating material 24 may be a ceramic insulator which will conduct heat but prevent shorting of the resistance element 23,-which would take place if it were to contactthe walls of tube 21.

An electric conductor 25 communicates with 'end 26 of the resistance element 23 and leads to a suitable elec tric connector plug 27 provided with contacts '28. A second'electrical conductor 29 leads from the end 30 of the heating element 23 to a thermostat 31 which is connected by a lead 32 with'the connector plug 27.

The casing 10 and the end walls 11, 12, the fins '15 andtube 21 may be of any suitable-heat conducting material. Aluminum is preferred because of its'lightness,

but steel, copper or other heat-conducting materials may be used as the material of construction of these parts.

Before the heater is placed in service, the connector plug 27 is connected to the household current line to supply current tothe resistance element-'23. at One or both of the plugs 17 are-removedfrom the end walls-11, 12. As the resistance element 23 heats up, the temperature within the casing 13 rises, causinggases therein, including water vapor which'ispresent in the air to be expelled through The resistance element 23 is:so :chosen that it;generates :temperatures above C., say about C., or somewhat higher at the voltage at which it is employed. If desired, a small amount of liquid may be introduced into the easing during this heating up period; this liquid, e. g., water, is vaporized and aids in efiecting removal of most, if not all, of the gases present in the zone 14. When the resistance element 23 reaches its steady temperature above 100 0, say about 110 C., and all of the added liquid, if any, has been expelled from the zone 14, the plugs 17 are reintroduced into the openings to seal the end walls.

Upon the removal of the connector plug 27 from its socket, the heater will cool to atmospheric temperature conditions, causing formation of a partial vacuum in the zone 14. This vacuum will generally be of the order of 6" of mercury but it will be understood the invention is not limited to this particular vacuum condition but it may be somewhat lower or higher.

\Nhen it is desired to heat a room, the plug 27 is inserted in an electrical socket connected with a current source, reheating the resistance element 23. Heat is conducted from this element 23 through the heat-conducting wall 21, heating zone 14 surrounding tube 21 within casing 10. This reheating of zone 14 creates a high-heat, low-pressure therein, the pressure still being below atmospheric but somewhat higher than the above-mentioned partial vacuum created when the heater is cooled to atmospheric or near atmospheric temperature.

It will be noted zone 14 completely surrounds tube 21; this tube is positioned just below the longitudinal axis of casing and spaced from the lower wall of this casing. As best'shown in Figure 3, the axis of tube 21 is substantially centrally positioned in the lower half of casing 10 on the vertical diameter D of this casing.

In operation it has been found that the heated lowpressure zone 14 acts as an efiicient heat transfer medium to heat the finned casing 10. The air of the room in proximity to the fins 15 and the casing 10 is thus heated, causing the heated air to rise with a consequent circulation of air in the room, and efficient heating of the room.

Thermostat 31 turns the current flowing to resistance element 23 on and off as the temperature fluctuates in the room to maintain the room temperature at the desired point; it will be understood this thermostat is of any well known type provided with a manual control so that it can be set to open or close a switch in the electrical circuit containing the resistance element.

It will be noted that the present invention provides an unusually simple, inexpensive, efficient electrical heater which may be, but need not be, portable and which is eminently suitable for use as a household heater. The heater is exceptionally safe in that the resistance element is enclosed within tube 21, is designed to generate temperatures that are not excessively high seldom above 110 C. and desirably of the order of 110-120 C., and the heater operates under subatmospheric pressure conditions in zone 14. Hence, the heater in operation involves no fire or explosion hazard. Since the resistance element 23 is enclosed Within the insulation 24 in tube 21, and since the air of the room in which the heater is disposed does not contact the resistance element but circulates over the casing 10 and the fins 15, the air in the room is not ozonized or otherwise deleteriously affected.

The exceptional simplicity of the heater should be evident from the above description. It will be noted that it involves the assembly of tube 21 containing the insulated resistance element in the casing 10. These parts can be produced at little expense and readily assembled resulting in a relatively low cost heater which, as noted, is highly eflicient in use. The only control required is the thermostat to control the temperature in the room at the desired level.

Once the heated vacuum zone has been created, it will remain as long as the casing 10 is maintained gas tight; it is rendered efiective whenever the electrical resistance unit is heated to operating temperature. Should the vacuum be destroyed for any reason, it is recreated as hereinabove described before the heater is placed in use to heat the room or other desired locality.

Since certain changes in the heater which embodies this invention may be made without departing from its scope, it is intended that all material contained in the above description or shown on the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. Thus, if desired, the fins on the casing wall may be eliminated. Also the heater may be so designed that it can be readily incorporated in the base of a wall to act as a baseboard or analogous heater. The heater may be used in conjunction with a fan or fans which blow air thereover to heat the air passing through a heating system. The heater may be portable or fixed to any suitable portion of the building in which it is disposed.

What is claimed is:

A heater comprising, in combination, a longitudinally elongated tubular casing of heat conducting material, defining a confined zone having at least one opening therein communicably connecting said zone with the surrounding atmosphere, a tubular heating member in said zone spaced from the heat conducting walls thereof, extending the full length of said casing and protruding from the opposite ends thereof, an electric resistance element in said heating member, an annular layer of insulation between said resistance element and said tubular member in contact with said resistance element and preventing access of atmosphere air to said resistance element, the assembly of tubular member, insulation and resistance element being positioned in the lower half of said casing with the axis of said tubular member substantially intersecting the vertical diameter of said casing, said casing having at least one opening in an end wall thereof disposed in the upper half of said end wall for communicably connecting the interior of said casing with the surrounding atmosphere, a

removable plug for sealing said opening, and electric conductors in circuit with a connector plug for placing said resistance element in circuit with a source of current.

References Cited in the file of this patent UNITED STATES PATENTS 

